Eco-friendly N-acyliminium ion chemistry: solvent-free HNTf2 and TIPSOTf-catalyzed α-amidoalkylation of silicon-based π-nucleophiles

N‐Acyliminium Ion Chemistry: Highly Efficient and Versatile Carbon–Carbon Bond Formation by Nucleophilic Substitution of Hydroxy Groups Catalyzed by Sn(NTf2)4

“…The inherent weak reactivity of the hydroxylactams was reflected by the requirement of 2-3 equivalents of the sensitive silyl enol ethers to provide high yields of adducts 3 (cf. In almost all of the examples high efficiency was observed examined (92-98 % yields) with 1.5-2 equivalents of the nucleophile; this emphasizes that 4 is more reactive than 1 (Table 1, entries [6][7][8][9][10][11][12]. [21] We next extended these studies to the reactions of the more reactive 2-hydroxy carbamate 4, and the results of coupling with several nucleophiles 2 a-e using Sn(NTf 2 ) 4 as the catalyst are summarized in Table 1, entries 7-13.…”

Metalltriflimidate sind bessere Katalysatoren für die organische Synthese als Metalltriflate – der Effekt eines stark delokalisierten Gegenions

“…[199][200][201] Sn(NTf 2 ) 4 (1 Mol-%) katalysierte die Allylierung von Hydroxylactam 52 zu 53 in 81 % Ausbeute (Schema 56). [202] Unter den getesteten Metalltriflimidaten war Sn(NTf 2 ) 4 am aktivsten.…”

Dual Hard/Soft Gold Catalysis: Intermolecular Friedel–Crafts‐Type α‐Amidoalkylation/Alkyne Hydroarylation Sequences by N‐Acyliminium Ion Chemistry

“…The reaction in the presence of AgOTf left the substrate untouched, which confirms that these alkylations are not promoted by silver catalysts (entry 10). Recognizing that a combination of AuCl and AgOTf might incidentally provide TfOH, which could act as a precatalyst by quickly generating TMSOTf as the true catalyst,9a,c a control experiment was performed by using 2 mol % of TfOH. The allylated adduct 3 a was produced in high yield, although a longer time was required than for the gold‐catalyzed reaction (45 min in entry 11 versus 20 min in entry 7).…”